Milling-machine.



J. R. JOHNSON.

MILLING MACHINE.

APPLICATION FILED SEPT. 9. 1913.

, 1,13 4% Patented May 11, 1915.

2 SHEETS-SHEET 1- THE NORRIS PETERS CO), PHOTLTLITMO.v WASHINGTON, D,

J. R. JOHNSON.

MILLING MACHINE.

APPLICATION FILED SEPT-9,1913.

l lwfl zfl Patented May 11, 1915.

2 SHEETS-SHEET 2.

llll'i ULIDY/QMWL 5 y gj "cw/5 PETERS 60., PHOTO-LITHO., WASHINGTON. D.C.

UNITED s rn rns ra rmvr OFFICE.

JOHN R. JOHNSON, OF ROCKFORD, ILLINOIS, ASSIGNOR TO THE ING-ERSOLLMILLING- IVIACI-IINE COMPANY, OF ROCKFORD, ILLINOIS, A CORPORATION OFILLINOIS.

MILLING-MACHINE.

Application filed September 9, 1913.

To all whom it may concern Be it known that I, JOHN R. JOHNSON, acitizen of the United States, residing at Rockford, in the county ofWinnebago and State of Illinois, have invented certain new and usefulImprovements in Milling-Wachines, of which the following is aspecification.

This invention relates to milling machines of the planing type, and hasmore particular reference to machines which embody a cutting bar orarbor which is driven from both of its ends.

In machines of this character it is customary to drive both ends of thecutter-bar or arbor from a common source of drive and to transmit thedrive through sepante trains of gearing at each end of the cutter-bar.Obviously, with a direct line of drive from a common source of power toeach end of the cutter-bar and with a pair of cutters mounted spacedapart on the cutter-bar, when one cutter is idle by reason of a gap inthe work operated upon, or for any other reason, the cutter in cuttingoperation will receive all the power and the cutter-bar intermediate itsdriven end and the operating cutter will be subjected to considerabletorsion.

My invention aims, primarily, to provide in apparatus of the characterdescribed, means for driving a cutter-bar whereby the same will be drien equally at both ends and the torsion will be proportioned equallythroughout the cutter-bar under varying conditions of the cutter.

It is desirable to connect each end of the cutter-bar with the drivenmember of. each train of gears through a square or angular socket andshank connection, the ends of the cutter-bar being shaped and receivedinto the sockets of the driven members. Since each of said drivenmembers is connected with the last gear of a train of gears which isdriven from a common source of drive, it is obvious that it is verydiflicult to properly aline the square socket of each driven member soas to receive the square ends of the cutter-bar when mounting the same,this difficulty arising, primarily, from variations in the play in thegear teeth. It is evident that with a fixed line of drive from a commonsource of power to both ends of the cutter-bar and with the socket notproperly alined, one end of the cutter-bar would re- Specification ofLetters Patent.

Patented May til, 1915.

Serial No. 788,800.

ceive very little, if any, driving power. These defects I aim to remedyby my invention, so that one of the driven members may be movedrelatively to the other to properly aline its socket with that of theother, and so that both ends of the cutter-bar will be driven equally,regardless of the variations in the mesh of the gears.

With the above considerations in view, I provide in the drive to bothends of the cutter, a sectional shaft driven by differential gearing,each section of the shaft having a driving connection with one end ofthe cutter-bar. By this means the drive transmitted to each end of thecutter-bar will be varied automatically according to the resistance ateach end of the cutter-bar, and a uniform drive will be had wherein thetorsion of the cutter bar will be equalized under varying conditions ofcutting. The driven members may also be moved rotatably with respect toeach other to aline the sockets when the cutter-bar is being mounted,and differences in the mesh of the gear trains will be automaticallycompensated for.

Another object of my invention is to provide in the above describedmechanism, clutch means for locking two members of the sectional shaftor driven members of the differential fixedly together whereby both ofsaid driven members may be fixed relatively and driven through a commonsource of drive, and also whereby either driven member may be drivenseparately when the cutter-bar is not used.

Referring to the drawings: Figure 1 is a face elevation of a millingmachine of the planer type embodying my invention. Figs. 2, 3, and 4:are sectional views taken on the lines 22, 33, and 4t4; of Figs. 1, 2,and 3 respectively, illustrating the differential drive means; and Fig.5 is an enlarged detail sectional view taken on the line 5 5 of Fig. 3.

In Fig. 1 I have illustrated briefly a milling mechanism of the planertype which comprises a bed 6, a table 7 slidably mounted thereon, sidehousings 8, and a cross-head 9 slidably mounted upon vertical ways onthe side housings for carrying a cutter-bar and driving means therefor.

Upon each side portion of the cross-head is mounted so as to moverotatably and axially a cutter spindle 10 and a train of step-clowngears 11 for rotating the spindle, the said spindles being coaxial. Asectional shaft comprising shaft connections 12 and 13 is journaledabove the said spindle in bearing 14, and each shaft section has adriving connection with one of the trains of gearing.

A differential gear driving mechanism is mounted in connection with theadjoining ends of the shaft connections 12 and 13 and may be of anysuitable construction, a suitable construction being illustrated in thedrawings, and constructed as follows: Sleeves l5 and 16 are splined uponthe inner ends of shaft connections 12 and 13 respectively, and haveformed respectively, at their inner ends spurgears 17 and 18. The innerends of said sleeves are also provided with serrated faces 19; andsleeve 16 is pro vided with an annularly grooved head 20 with whichgroove a yoked member 21 cooperates and may be operated in any suitablemanner to move the said sleeve 16 axially to engage and disengage theserrated faces 19. Circular casings 22 and 23 are mounted loosely uponthe sleeves 15 and 16 respectively, forming a gear and an inclosedcircular housing, the casing 22 being provided on its periphery with aspur gear A pinion spur gear 25 meshes with said spur gear 24: and maybe driven by a motor 26 or any suitable driving means. A plurality ofpairs of cross-shafts 27 are mounted in the casings 22 and 23, and eachpair has a spur pinion gear 28 mounted upon one shaft in mesh with thespur gear 17, and a spur pinion gear 29 on the other shaft in mesh withthe spur gear 18, the said pinion gears 28 and 29 being in meshintermediate said gears 17 and 18.

A cutter-bar or arbor designated by the reference character 30 isjournaled intermediate its ends in a bearing 31 mounted upon the crosshead 9 and has its ends formed square as at 32, and received into squaresockets in the spindle members 10, whereby the cutter-bar may be drivenby the driving means above described. Cutting tools may be mounted uponthe cutterbar in any order desirable, there being illus trated in Fig. 1a pair of cutters arranged so that each cutter may operate upon workcarried at each side portion of the table 7.

In the operation of the machine, assuming that both cutters on thecutting-bar or arbor are in cutting operation upon work carried by thetable and have equal resistances, the shafts 12 and 13 will likewisehave equal resistances. Since these shaft sections are the drivenmembers of a differential gear mechanism, said mechanism will be drivenas a unitary member; that is, the casings 22 and 23, gears 17 and 18 andgears 28 and 29 will be rotated as one member and without relativerotary movement of any of the driving power would be applied.

gears. Should the work carried by the table without resistance, orshould the resistances.

of the two cutters be unequal for any other reason, the unequalresistances of the cutters would be transmitted to the shaft sections 12and 13. Under these conditions the differential driving mechanism wouldso transmit power to the two shaft sections asto equalize the drivingpower between said shaft sections, and thereby equalize the driveapplied at both ends of the cutterebar. Taking for an example, it may beassumed that the cutter at the right in Fig. 1 is working idle oragainst less resistance than is the other cutter, in which case thetendency would be for the greatest torsion on the cutter-bar to be foundintermediate its left driven end and the cutter adjacent thereto, uponwhich end the blunt of Tthle e heavy resistance falling on the leftcutter would be transmitted to the gear 17 of the differential. Theretardation of this gear 17 would cause such retardation to betransmitted through gears 28 and 29 to accelerate the speed of gear 18,or, in other words, to transmit greater power to gear 18 and to theright end of the cutter-bar because of its lesser resistance. This is acommon action of differential mechanism. Thus the driving power from themotor would be automatically equally disposed to both ends of thecutter-bar, and the higher torsion on the cutter-bar intermediate itssaid left end and the cutter adjacent thereto would be proportionedsubstantially equally throughout the length of the cutter-bar.

WVhen setting up the machine it is practically impossible to aline thesockets in the spindles 10 so that they will receive the square ends ofthe cutter-bar and drive the same in the proper manner, because of theunevenness in the mesh of different trains of gears. It is obvious thatthe relative rotary movement of the spindle 10 to aline the said squaresockets may be had through the differential gear mechanism; also,variation in the mesh ofthe different trains of gears will becompensated for through the differential action of said mechanism, sothat (the resistance of the cutters being the same) each end of thecutter-bar will be driven with the same amount of power.

While I have shown and described a preferred embodiment of my invention,I do not desire to limit myself to the specific embodiment shown, sincevarious changes in the structural details may be resorted to within thescope of the appended claims without departing from the spirit of theinvention or sacrificing any of its material advantages.

I claim as my invention.

1. In apparatus of the character set forth, the combination of a cutterholding bar, and means for driving said bar at both ends ineluding adifferential gearing through which power is transmitted.

2. In apparatus of the character set forth, the combination of a cutterholding bar and a common drive connection including a differentialgearing connected with both ends of said cutter holding bar.

3. In a milling machine, the combination of rotatable cutter spindles,cutter holding means connecting the spindles, a driving connection forrotating both spindles, and a differential gearing operably connected tosaid driving connection and adapted to be driven to drive said drivingconnection.

4. In a milling machine, the combination of two rotary cutter spindles,means rigidly connecting the spindles, and a differential mechanism fordriving said spindles.

5. In apparatus of the character set forth, the combination of arotatable cutter holding bar, driving means for rotating said bar fromboth ends thereof, and means for automatically equalizing the torsionalresistance of said driving means coming from both of said bar ends.

(3. In apparatus of the character set forth, the combination of arotatable cutter holding bar, a sectional drive shaft, each sectionhaving a driving connection with an end of said cutter bar, and meansfor rotating said shaft sections with an equal force and allowing rotarymovement of one section with respect to the other.

7. In a milling machine, the combination of two rotary cutter holdingspindles, means rigidly connecting said spindles, a difierential geardriving mechanism having each of its two driven members in drivingconnection with one of said spindles, and means for fixedly connectingsaid two driven members whereby they will rotate together.

8. In apparatus of the character set forth, the combination of a cutterholding bar, two

driving connections each in connection with one end of the said bar, adifferential drive connecting said two driving connections, and meansfor locking said two driving connections fixed rigidly together.

9. In apparatus of the character set forth, the combination of a rotarycutter-holding bar, and driving means for driving said bar at both endsthereof including differential mechanism for driving said ends as tomaintain the torsion of the bar equal throughout the length thereofregardless of variations in cutting resistances from cutters atdifferent points on the cutter-holding bar.

10. In a milling machine, the combination of a pair of spaced andcoaxially mounted cutter spindles, a two-section shaft mounted parallelwith the axes of said spindles, a train of gears connected to eachcutter spindle and a shaft of said sectional shaft, and a differentialdriving mechanism connected to the sections of the sectional shaft fortransmitting difl'erential drive to the same.

11. In a milling machine, the combination of a pair of spaced coaxiallymounted cutter spindles, cutter holding means interposed between andconnected to said spindles, a train of gearing connected to eachspindle, and a differential driving mecha nism having a drivingconnection with each train of gearing for transmitting differentialdrive thereto.

12. In apparatus of the character set forth, the combination of a rotarycutterholding bar, a two-section drive shaft, each section having adriving connection with an end of the cutter bar, means for driving saidshaft sections by a differential driving mechanism, and means for movingone of the shafts axially to engage fixedly with the other shaft.

In testimony whereof I have hereunto set my hand inpresence of twosubscribing Witnesses.

JOHN F. MCOANNA, Jr., E. D. E. N. BEHEL.

Gopies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. 0'.

It is hereby certified that in Letters Patent No. 1,139A22, granted May11,1915,

upon the application of John R. Johnson, of Rockford, Illinois for animprovement in lVIilling-hzlaehines, errors appear in the printedspecification requiring correction as follows: Page 3, line 10, afterthe Word bar insert a comma; same page, line 59, after the Word forinsert the Word 80; same page, line 7 8, after the Word spaced insertthe word and; and that the said Letters Patent should be read with thesecorrections therein that the same may conform to the record of the casein the Patent Oflice.

Signed and sealed this 1st day of June, A. D., 1915.

J. T. NEWTON,

Acting Commissz'mer of Patents.

[SEAL]

